ST. LOUIS — The Jets offense has looked downright inept in recent weeks, but their defense is trying to guard against the feeling it needs to be dominant for the team to win.

“You don’t want to get into that mentality,” defensive coordinator Mike Pettine said. “I think that’s the case, but you don’t want to preach that to the guys.”

Pettine said he saw bad things happen when he was a Ravens assistant and Ed Reed & Co. began to press in order to pick up their struggling offense.

“Guys on defense felt like, ‘You know what, I have to make a play to win the game,’ ” Pettine said of the Ravens. “That’s when you get hurt. That’s when a corner jumps a slant and it’s a slant and go.”

The Jets defense has not been as dominant this year as Pettine’s first few years with the team, as the unit ranks 17th in the NFL.

During the 28-7 loss to the Seahawks, the defense played three good quarters, but the offense failed to score a point. Pettine said he has spoken to his players about not pointing fingers at the offense or worrying about whether Tim Tebow should be replacing Mark Sanchez at quarterback.

“If you have all pluses on your grade sheet then you can go talk about the offense,” Pettine said. “Are you batting a thousand?”

One thing Pettine has emphasized since the bye week is forcing fumbles. The Jets coaches looked at the Bears, who have forced 30 turnovers this year.

Pettine had the defense watch video on how to strip ballcarriers. It began with two plays by the Bears, followed by 15 plays made by the Jets over the last 3 1/2 years.

“We said if we want to be a dominant defense and help our offense out, we’ve got to get the ball back,” Pettine said. “We can’t be content to give up a couple of first downs and get a punt. We have to be more aggressive attacking the football. We control that. I think our guys did a real good job and they’re doing it in practice. The scout team running backs are hating life right now because they’re getting mugged.”

The defense has also started treating incomplete passes in practice as fumbles, picking them up and running with them to reinforce the instinct of picking up any ball on the ground.

* Pettine is very upset about the loss of cornerback Isaiah Trufant to a season-ending knee injury, and said the 5-foot-8 Trufant, who had emerged as the team’s nickel corner, always graded out near the top of the defense.

“If he’s 4 or 5 inches taller, he’s a Pro Bowler,” Pettine said. “Everybody just looks at him and writes him off because he’s tiny.”

* Safety LaRon Landry said he feels bad for Tebow, who dealt with an anonymous attack this week.

“For Tim, you have to understand how he feels,” Landry said. “He has to look in certain people’s eyes and he doesn’t know who said it. It’s a two-faced deal. It could have been all make believe.”

The Jets, who are 0-2 against the NFC West this year, never have lost four games in a row under Rex Ryan.